Condensed Consolidated Balance Sheets (Unaudited) Parenthetical - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Investment securities held to maturity, estimated fair value	$ 1,142,694	$ 1,182,009
Loans held for sale, fair value	$ 74,741	$ 105,257
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, liquidation preference (in dollars per share)	$ 200,000	$ 200,000
Preferred stock, number of shares authorized	30,000,000	30,000,000
Preferred stock, number of shares issued	1,150	1,150
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, number of shares authorized	300,000,000	300,000,000
Common stock, number of shares issued	222,950,751	222,950,751